40 CFR § 1501.6 - Findings of no significant impact.
(a) An agency shall prepare a finding of no significant impact if the agency determines, based on the environmental assessment, not to prepare an environmental impact statement because the proposed action will not have significant effects.
(2) In the following circumstances, the agency shall make the finding of no significant impact available for public review for 30 days before the agency makes its final determination whether to prepare an environmental impact statement and before the action may begin:
(i) The proposed action is or is closely similar to one that normally requires the preparation of an environmental impact statement under the procedures adopted by the agency pursuant to § 1507.3 of this chapter; or
(ii) The nature of the proposed action is one without precedent.
(b) The finding of no significant impact shall include the environmental assessment or incorporate it by reference and shall note any other environmental documents related to it (§ 1501.9(f)(3)). If the assessment is included, the finding need not repeat any of the discussion in the assessment but may incorporate it by reference.
(c) The finding of no significant impact shall state the authority for any mitigation that the agency has adopted and any applicable monitoring or enforcement provisions. If the agency finds no significant impacts based on mitigation, the mitigated finding of no significant impact shall state any enforceable mitigation requirements or commitments that will be undertaken to avoid significant impacts.